This research aims to demonstrate the viability of actively controlled distributed-electric propulsion as a method to postpone flutter in high aspect-ratio elastic wings. A semi-wing on a spring mount with two propellers powered by electric motors, mounted at alternate pitch angles relative to the chord line, was used as the...
In order to estimate wind turbine residL2;characteristics
in the presence of atmospheric turbulence, the important atmospheric
sources for the force excitations felt by the wind turbine system
must be identified and characterized. The goal of this research
is to develop the wind turbulence input model for horizontal axis
wind turbines....
An experimental study was made of the average and turbulent
wind characteristics of the flow over a model of a coastal headland.
The scale of the model was 300:1, corresponding to a prototype size
of 500 m.
The data for validation of the model study was obtained from
instruments mounted...
The amount of energy we use and the ways that we get that energy sit on the edge of dramatic change as the carbon budget which can keep the planet under 1.5C of global average temperature increase gets smaller (Allen, 2018). In response, we continue to research and develop renewable...
With the need to integrate renewable energy sources into the current energy portfolio and the proximity of many population centers to an ocean coastline, it is pressing that marine energy systems, specifically wave energy converters (WECs), are evaluated as potential solutions for meeting energy needs. In order to best understand...
Realizing the vast amount of energy available in ocean waves, an industry has emerged that is progressing towards the deployment of grid–connected wave energy converters. Likely to be deployed in arrays, a challenge to the wave energy industry is maximizing the energy production of such arrays. We have been developing...
The intent of this report is to provide a brief description of water quality issues in Nicaragua, Uganda and Bangladesh, and the technologies available to address these issues. The water quality parameters considered include: bacterial contamination, heavy metals and arsenic, pesticides and industrious chemicals, turbidity, radiological characteristics, and taste and...
Vortical structures are the driving mechanism of transition to turbulence in porous media requiring adequately resolved observations along with analysis of the scale and energy of flow within the pores. Of specific interest is to understand the vortex dynamics, energy, and turbulent mixing and transport properties in the scale of...
Integrated Distributed Electric Augmented Lift (IDEAL) applies upper-surface blowing in a novel way using an array of electric ducted fans (EDFs) to achieve electric short take-off and landing to meet the growing need for urban air transportation. Additional research on the use of vortex generators (VGs) to reduce flow separation...
The volumetric receiver is an advanced solar central receiver
concept designed to produce high temperature air. This document
presents the results of a heat transfer and performance evaluation of
the volumetric receiver concept.
The volumetric receiver consists of an array of ceramic fins or
fibers arranged in concentric rows around...
Two-phase flow in a fractal-like branching microchannel heat sink may have
enhanced heat transfer capabilities over single phase flow in the same branching
channel network. In order to exploit this potential, a complete understanding
of flow boiling in this geometry is required. The fractal-like geometry is similar
to that of...
Hydrodynamic effects play important roles in fluidized bed
combustion processes. Since the motion of "bubbles" is an important
influence on fluidized bed heat transfer, a better understanding of their
behavior is necessary for improving the design of fluidized bed boilers.
Using a two-dimensional bed, silica sand particles were fluidized with...
The equations of motion of an elastic cable suspended in a
viscous medium from two arbitrary points are derived. These are
then linearized for the undamped, inextensible case, and it is found
that the equations describing the in-plane motion of the cable are
then independent of the equation describing the...
Vertical Axis Pendulum Wave Energy Converters (VAPWECs) are thought to be both effective and robust at converting ocean wave energy into usable electricity. Seeking to build upon and investigate such potential, this work examines the merits of actively controlling a generic VAPWEC's pendulum for the purpose of increasing the converter's...
Several standardized courses for Formula SAE (FSAE) testing are introduced and described with sufficient detail to be reproduced by any Formula SAE team. Basic analysis methods for the courses are given as well as explanations of how those analyses could be used. On-car data from the Global Formula Racing (GFR)...
Aperiodic structures cause significant challenges to subtractive manufacturing methods due to the common features such as inaccessible voids within the structure. Additive man- ufacturing presents an appealing alternative for this purpose. The aim of this research is to test analysis heuristics for validity through application to periodic structures. First, a...
Formula SAE is a collegiate engineering competition that has participants from around the globe. Of the 1000 points available throughout the event, 100 (10%) are dedicated to the fuel efficiency of the student built race cars. Competition rules allow either gasoline or E85, a mix of 85% ethanol and 15%...
Over the last few decades, the methods and tools through which humans collaborate, share knowledge and generally communicate have been advancing at a rapid pace. Thanks mostly to advances in broadband internet, cheap data storage and fast microprocessors, humans now have the ability to work together in ways that even...
Modern walking robots have shown that dynamic gaits can be achieved without ankle motors. It seems logical that the additional control authority that they provide can be used to improve the stability of the walking gait against foot placement errors caused by low level control. This thesis develops and compares...
A sawmill is similar to other manufacturing enterprises when it comes to making decisions, scheduling production and meeting customer demands. In order to help sawmills achieve their goals, and because there is such a high degree of variability in the raw material used in this industry, computer simulation has proven...
Considering human factors in early engineering design stages can improve expensive late stage processes, facilitate user safety, improve product quality and help reduce the need for physical prototyping. Currently, car pillar design (the vertical pillars between windows which connect the roof and car body) provide safety for the passengers in...
Sustainable product design is becoming an important component of the development of consumer products. Currently there are limited design resources to aid in the creation of environmentally sustainable products. The purpose of this research is to theorize a new method for integrating sustainable design knowledge into the early design phase...
The second law of thermodynamics, through the exergy
concept, allows us to quantify and rationally cost the
consumption of exergy (irreversibility) used to drive the
heat exchange process and the effluent losses of exergy in
a heat exchanger For systems with a network of heat
exchangers, the exergy concept recognizes...
This dissertation details the application of digital image correlation (DIC) in novel methods for mechanical testing and shape characterization. The first usage manifested in the development of a novel composite test specimen that provided the ability to characterize the matrix compression energy release rate at initiation and subsequent crack propagation....
There is a growing US interest in UAVs for many applications ranging from agriculture to military. One area of improvement that can be realized in each category is propulsion. Engines with greater efficiency would result in longer mission duration, leading to cost savings and increased usefulness for UAV owners and...
This project created a stand-alone unit capable of providing on-board sensing and processing for robotic vehicles. This unit was designed to be compact, lightweight, inexpensive, and adaptable. The goal of this project is to help advance robotics research in mapping and multi-agent coordination by making it easier to equip vehicles...
Analysis of alternative concepts has a significant impact on design project outcomes, and yet many design teams fail to consider a significantly broad range of conceptual solutions. Within the realm of conceptual design exists a technique called design by analogy (DBA) -- the practice of reapplying old solutions to new...
The Oregon State University (OSU) Advanced Plant Experiment (APEX) is a one-fourth height, one-half time scale, reduced pressure integral systems test facility designed to model the long-term cooling capabilities of the emergency core cooling systems of the Westinghouse AP600. This study provides a brief description of the APEX test facility,...
The development of a continuous and reliable cooling method for computer chips is an evolving subject requiring continuous research in both computer science and thermal management. Two-color laser induced fluorescence (LIF) provides a non-invasive way to investigate electronics cooling fluid behavior. Dielectric fluids are of particular interest as they allow...
This study investigates the atmospheric flight dynamics of a munition system and the effect of a tether reel resistance mechanism for limiting the impact that the unreeling process has on the munition system. The munition system consisting of two projectiles connected by a tether line is released from an aircraft...
The purpose of this project is to assist the OSU Baja Racing vehicle in turning more sharply. This is done using a turning brake, which locks one rear wheel to facilitate turning on a smaller radius. This project focuses on the development of a custom cylinder housing for the turning...
Seven decades of supercritical heat transfer research have not seen an attempt to characterize turbulent thermal transport in internal flows subject to asymmetric heating. Existing heat transfer models therefore do not account for phenomena that dictates thermal transport, in the proximity of the pseudo-critical point, for non-uniform heating. Additionally, past...
The aviation industry is pushing for better fuels and gas turbine engines for several reasons: cost, emissions, and to a lesser extent high-altitude relights. One aspect that research has been focused on to help reduce costs, emissions and better understand high-altitude relights is studying the combustion behavior of the fuel...
Development of variable speed horizontal axis wind turbines has resulted in a need for an analysis code with a rotor speed degree-of-freedom. This study develops a five degree-of-freedom time domain computer code that evaluates blade and rotor, mean and cyclic loads with nonlinear aerodynamics together with atmospheric turbulence as a...
After traveling to Africa and experiencing the struggles and confusion of interacting with a new culture, I saw the need for some sort of orientation device that would adequately prepare first timers, but also not be too lengthy and daunting for a person that will only be spending a few...
An important element in rector safety and fuel performance assessments is the efficient calculation of the time dependent temperature profiles within reactor fuel pins. Because the fuel pins have temperature dependent thermal properties, the governing partial differential equations are nonlinear. Traditionally, finite difference or finite element methods have been used...
This paper deals with the thermal decompositon of
wood slabs under fire conditions. The partial differential
equation is solved numerically by the use of an implicit
finite difference method. Wood is treated as two
components, Lignin and Hemicellulose on one side, and
Cellulose on the other side. The chemical reactions...
Only very recently has modern technology been applied
to the design of the tennis racket. In fact, the tennis
player of a few hundred years ago would easily recognize
today's racket. Although the literature reveals a surprising
number of studies on racket mechanics, little work has been
reported on the...
Integrated Distributed Electric Augmented Lift (IDEAL) applies upper surface blowing in a novel way to achieve electric short take-off and landing to meet the growing need for urban air transportation. Additional research on propulsion airframe interaction (PAI) with trailing edge flaps at low Reynolds numbers was necessary to advance the...
Laser Powder Bed Fusion (LPBF) is a process commonly used to create additively manufactured metal parts. The flexibility and complexity allowed by the LPBF process provides opportunity for significant advancement in multiple industries as parts can be customized in shape and function for specific needs. These benefits can be compounded...
Ocean wave energy is a new and developing field of renewable energy with great potential. The energy contained in one meter of an average wave off the coast of Newport Oregon could supply dozens of homes with electricity. However, ocean waves are usually quite irregular which leads to large bursts...
This work proposes a framework of concept generation and evaluation that takes into consideration the benefit of creativity and innovation in current market trends. By educating engineers in how to increase creativity in concept design and assess it quantitatively, the next generation of designers will be a step ahead of...
Topology optimization (TO) is a mathematical method to find the optimal size, shape and connectivity of a domain under specified conditions, and has had many applications in engineering design. However, challenges remain in realizing TO as an effective design tool for many design situations. Uncertainty is ubiquitous in nature and...
The “why” of any situation is one of the most important questions to ask. Inventors have ideas every day. Some ideas are the brilliant ideas that lead to a better tomorrow. To protect these ideas, inventors turn to patents, a governmental grant of the right to stop others, for a...
Wave energy conversion is still in its infancy, and in order for it to become a commercially viable technology, developers, investors and utilities need to estimate a Wave Energy Converter's (WEC's) performance for the wave climate of a potential installation site. With the goal of estimating a design's power output...
Polymeric composites exhibit time-dependent behavior, which raises a concern
about their long term durability and leads to a viscoelastic study of these materials.
Linear viscoelastic analysis has been found to be inadequate because many polymers
exhibit nonlinear viscoelastic behavior. Classical laminate theory is commonly used in
the study of laminated...
Pulsed laser deposition was used to create 0.1-Bi(Zn₀.₅ Ti₀.₅)O₃-0.9-BaTiO₃ (BZT-BT) thin films to examine the effects of laser energy (2.25 or 2.5 J/cm²) , pulse frequency (2 Hz or 5 Hz), and deposition temperature (550, 600, 650, and 700°C) on the electrical properties of the films. These effects were analyzed...
Freezing is one of the important technologies for preservation of foods.
In this project, using surimi as a food model, thermophysical properties of frozen
foods were evaluated and the freezing process was simulated using a finite
element package.
To measure temperature-dependent thermal conductivity, a line-source
probe system was used. Effects...
Non-destructive testing is a methodology to inspect production and operational parts for potential flaws, defects, or damages. The present work is based on pulsed wave thermography, a thermal imaging method based on heat conduction to identify surface and subsurface defects potentially present in a component. Pulsed wave thermography applies a...
A thermodynamic analysis of forced geoheat recovery from aquifers
has been accomplished. The system investigated consists of a single
recharging-discharging well pair, in a horizontally extensive aquifer,
with either power generation or space heating as surface applications.
The space heating systems investigated are (i)direct heating, (ii)heat
pumps and (iii)a combination...
An experimental study of thermally actuated pumping of a single-phase, single-component fluid is presented in the context of thermal management of a heat source. The prominent feature of this pumping method is that the very heat that is to be removed from the heat source causes a net fluid motion....
This thesis is concerned with designing and simulating waste
energy retrieval systems from large transformers to provide heating and
cooling of a control house. The transformer selected is Transformer
Bank One at the Ross Substation in the BPA system. The unit is an
ASEA 250 MVA transformer with forced oil,...
The thermal contact conductance (TCC) between two machined pieces of stainless steel was studied. A guarded hot plate thermal conductivity test fixture was designed and built for the experiment. Factors investigated included the contact pressure, surface roughness, interface material and average test temperature. The contact pressure at the interface ranged...
A phase sensitive measurement technique that permits the simultaneous determination
of two independent thermal properties of thin dielectric films is presented. Applying the technique results in a film's thermal diffusivity and effusivity, from which the thermal conductivity and specific heat can be calculated. The technique involves measuring a specimen's front...
"Piping Design and Engineering" first published in 1963 by
Grinnell, Co. is widely used by engineers to perform approximate
thermal stress analysis of high-temperature piping systems. The
text consists of numerical constants to calculate end reactions and
maximum bending stresses in a variety of piping configurations from
known properties of...
Breakthroughs in heat sink design are now limited by conventional manufacturing techniques which can only produce basic fin shapes with homogenous surface structuring. Additive Manufacturing (AM) is a potential disruptive technology for heat sink design and other convective heat transfer solutions, as surface properties can be directionally varied to maximize...
Desalination stands for removing salt from saline water, and produce freshwater. Desalination technologies have been envisioned as a potential solution for freshwater production from oceans as an immense source of water acquiring 97% earth’s water, and 75% of earth’s surface. However, one third of world’s population face water scarcity every...
A number of computational tools now exist to aid in developing conceptual solutions based on a functional description of a design problem. A key limitation of these tools is the way results are organized for presentation to the user. In general, results are an undifferentiated mass of potential solutions. Analysis...
Development of micro air vehicles has led to a strong interest in the biomechanics of flapping fliers such as bats, birds, and insects, due to their ability to perform extreme unsteady maneuvers and fly in confined spaces. Determining the methods and mechanisms used by these fliers is a valuable source...
Multiagent learning with cooperative coevolutionary algorithms is a critical area of research, and is relevant to many real-world applications including air traffic control, distributed sensor network control, and game-theoretic applications such as border patrol. A key difficulty in multiagent learning is the credit assignment problem, where the impact of each...
The substantial wave energy resource of the US Pacific Northwest (i.e. off the coasts of Washington, Oregon and N. California) is assessed and characterized. Archived spectral records from ten wave measurement buoys, operated and maintained by the National Data Buoy Center and the Coastal Data Information Program, form the basis...
In the wake of climate change, the risk of heat related illnesses has continuously increased over the past several decades. While thermal management solutions have continued to improve, there is a need for efficient cooling systems that conform with the human body. This study combines the solutions from fractal-like flow...
In the construction of a rifle for sporting or target work
there are several conditions to be met. In the first place the
rifle must be made to balance easily.at all times, whether the magazine
is full of loaded cartridges or is empty. In all cases the
barrel of the...
Modern engineered systems are increasingly integrated into society, decentralized, and interconnected. However, scale and complexity create unique challenges in system design, such as emergent behavior and unintended consequences. This work investigates the structural characteristics of robustness in complex engineered systems by identifying patterns of under-recognized vulnerabilities at various levels of...
The zirconium-chromium phase diagram was investigated in the
region between 40% and 85% chromium. The ZrCr₂ intermetallic
compound which has been the source of some controversy was especially
considered. It was found that ZrCr₂ transforms from the low
temperature C-15 (MgCu₂, FCC) structure to the high temperature
C-14 (MgZn₂, HCP)...
In this paper, I present the design of Mira 2, a small-scale, liquid bipropellant rocket engine, with a specific focus on its oxidizer-centered pintle injector. Building upon the valuable lessons and insights gained from the empirical testing of its predecessor, Mira 1, the Mira 2 engine incorporates several improvements and...
A new thermal management method for hotspots on microprocessors is under development that employs confined pool boiling with vapor extraction at pre-determined nucleation sites. Extraction is accomplished by locating a vacuum chamber constructed out of a glass tube and a hydrophobic membrane directly above a nucleation site. In order to...
Smoldering can play a dangerous role in the ignition and spread of wildfires. Naturally occurring fuels consist of multiple layers of organic materials with varying particle sizes due to differences in decomposition stages with fuel depth, yet the influence of particle size on burning behavior is poorly understood. Previous research...
As carbon emissions are negatively impacting ecosystems across the globe, researchers are in a race against time to provide cleaner and more eÿcient power. Detonation engines can help meet the increasing demands for cleaner and more eÿcient power generation by providing an alternative means to use oxy-fuel combustion for carbon...
Large-hydrocarbon fuels are used for ground and air transportation because of their high energy-density and will be for the foreseeable future. However, combustion of large-hydrocarbon fuels in a turbulent environment is poorly understood and difficult to predict. The turbulent flame speed, which is the velocity at which a flame front...
Rising energy demands and the continual push to find more energy efficient technologies have been the impetus for the investigation of waste heat recovery techniques. Diesel engine exhaust heat utilization has the potential to significantly reduce the consumption of fossil fuels and reduce the release of greenhouse gases, because diesel...
This research presents a methodology to identify and analyze human-system interactions, and their potential failure modes using a functional decomposition approach during the early system design stage.
The fundamental research contribution of this work is the development of a framework to identify associations between physical user-product interactions, generic human errors...
In many composites, fiber bridging develops as part of the fracture process. Fiber bridging invalidates many toughness evaluation methods such as the ASTM E399 and complicates the identification of crack length, which is a necessary parameter in energy methods. In order to measure the toughness of fiber bridging composites, an...
Hydrogen is an increasingly attractive low-carbon energy carrier for a variety of stationary and mobile applications. Currently, the vast majority of hydrogen in the United States is produced via the energy intensive steam reforming of natural gas. The cost and carbon emissions associated with hydrogen production can be reduced by...
People often grow increasingly culturally confused when spending significant amounts of time in a foreign land. Identity can become lost only to reform in the image of the host society. This thesis presents a creative nonfiction series of essays that explore the author’s loss of self and contextual identity, the...
Understanding the behavior of hydrophobic membranes is important for applications where separating a gas from a liquid-gas mixture is beneficial. For example, in-situ vapor extraction can be used in microscale heat sinks to improve heat transfer and flow stability. In this study, gas is experimentally evaluated flowing through flexible polytetrafluoroethylene...
The world is currently using an unsustainable system of meeting its transportation
needs with oil. This system is taking a toll on the world environment and on global politics.
The physical availability of oil is the system’s most immediate problem and will most likely
bring about a transition away from...
The aerodynamic performance of an oscillating pitching and plunging foil operating in the energy harvesting mode is investigated. Experiments are conducted in a closed-loop recirculating wind tunnel at Reynolds numbers of 24,000 to 48,000, and reduced frequencies (k = fc/u) of 0.042 to 0.083. Foil kinematics are varied through the...
A study was conducted to determine what effects the type of
pollutants, storage conditions, storage time, and method of sample
conditioning have on the reported weight of an air pollutant collected
by filtration. Samples were collected from a refuse dump, an arc
furnace smelting nickel ore, and a rotary kiln...
This study determined the independent effects of various homogenization cycles and
precipitation treatments on the elevated temperature workability and the final ambient
temperature mechanical properties of AA2024 aluminum alloy and on the T3 tensile
properties of 2014 aluminum alloy as well as T6 tensile properties of 2618 and 2618 (Curich)...